Place a plate in the freezer (for the molds to sit on later).
Melt chocolate in a microwaveable bowl on high for 60 seconds.Stick a spoon in the chocolate to see if it's beginning to melt. If it is you will need to decrease the power percentage on your microwave down to 60 percent and continue.
Continue to warm up chocolate in 30 second intervals stirring between each time.
Once the chocolate is melted, heat for 15 seconds and stir until all lumps are gone and the chocolate is smooth.
Use a pastry brush to drop a dollop of melted chocolate into the first cavity of the silicon mold. Coat the mold completely and wipe away any excess chocolate.
Freeze for 10-15 mins.
Remove plate and mold from the freezer.Carefully remove each half from the mold and set them on the now cold plate (this keeps them from melting)
Spoon in 2 tablespoons of cocoa mix into half of the molds. Add mini marshmallows and sprinkles if desired, but keep in mind that not all candy and sprinkles melt. While it is nice for presentation, be selective on what you put inside of your hot cocoa bombs. Some sprinkles may be a choking hazard to small children.3
Carefully connect the two ends of the heart together by placing the top half onto a heated plate to lightly melt the edges. Stick the halves of the chocolate sphere together. ( I put a plate into the microwave for 20 seconds. )
Let bombs set before attempting to add piping get.
To use the bombs, place a bomb in a large mug of hot milk and stir.